tools/gn: move the implementation of IsIdentifierXXX functions to the source file

tools/gn: move the implementation of IsIdentifierXXX functions to the source file

Does not seem to have a reason to have some functions implemented in the
header while the others are in the source file.

This also allow us to remove the include of string_util.h, and have it
included only in the source file.

BUG=None
R=scottmg@chromium.org

Committed: https://crrev.com/0c60e3a9bb46ef9f3cf92f90f3e6fde598f3b8ee
Cr-Commit-Position: refs/heads/master@{#362285}

[tfarina, 2015-11-30 22:14:46]

PTAL

[scottmg, 2015-11-30 22:25:45]

lgtm

[tfarina, 2015-11-30 23:31:45]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2015-11-30 23:37:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1483903004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1483903004/1

[commit-bot: I haz the power, 2015-12-01 00:10:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-01 00:12:22]

Description was changed from

==========
tools/gn: move the implementation of IsIdentifierXXX functions to the source
file

Does not seem to have a reason to have some functions implemented in the
header while the others are in the source file.

This also allow us to remove the include of string_util.h, and have it
included only in the source file.

BUG=None
R=scottmg@chromium.org
==========

to

==========
tools/gn: move the implementation of IsIdentifierXXX functions to the source
file

Does not seem to have a reason to have some functions implemented in the
header while the others are in the source file.

This also allow us to remove the include of string_util.h, and have it
included only in the source file.

BUG=None
R=scottmg@chromium.org

Committed: https://crrev.com/0c60e3a9bb46ef9f3cf92f90f3e6fde598f3b8ee
Cr-Commit-Position: refs/heads/master@{#362285}
==========

[commit-bot: I haz the power, 2015-12-01 00:12:22]

Patchset 1 (id:??) landed as
https://crrev.com/0c60e3a9bb46ef9f3cf92f90f3e6fde598f3b8ee
Cr-Commit-Position: refs/heads/master@{#362285}